NonStop NS16000 Series Planning Guide (H06.11+)

Using OSM for Down-System Support
In Integrity NonStop NS16000 series systems, the maintenance entity (ME) in the p-switches provides
dedicated service LAN services via the OSM Low-Level Link for both OS coldload, system
management, and hardware configuration when hardware is powered up but the OS is not running.
LAN connections are direct from the maintenance PIC in slot 1 of the p-switch to the maintenance
switch that is installed in the modular cabinet. This illustration shows the LAN connections for the
OSM Low-Level Link:
AC Power Monitoring
For Integrity NonStop NS16000 series servers, you can use one of the following to provide
continued system operation through a power failure. However, to take advantage of OSM power
fail support, you must use the HP R5000 UPS. When used, it is connected to the system’s dedicated
service LAN via the maintenance switch through which OSM monitors the power state.
• Optional HP R5000 UPS (with one or two ERMs for additional battery power)
• User-supplied UPS installed in each modular cabinet
• User-supplied site UPS
If a user-supplied rack-mounted UPS or a site UPS is used rather than the HP-supported UPS models
mentioned above, the system is not notified of the power outage. Operators are responsible for
detecting power transients and outages and developing the appropriate actions, which might
include a ride-through time based on the capacity of the site UPS and the power demands made
on that UPS.
The R5000 UPS and ERMs installed in modular cabinets do not support any devices that are
external to the cabinets. External devices can include tape drives, external disk drives, LAN routers,
and SWAN concentrators. Any external peripheral devices that do not have UPS support will fail
immediately at the onset of a power failure. Plan for UPS support of any external peripheral devices
that must remain operational as system resources. This support can come from a site UPS or
individual units as necessary.
OSM Power Fail Support
When properly configured, OSM provides important power fail support for Integrity NonStop
NS16000 series servers. OSM detects power outages and helps you take appropriate actions in
the event that the outage lasts longer than the estimated capabilities of your UPS.
When OSM detects that one power rail is running on UPS and the other power rail has lost power,
it logs an event and begins counting down the ride-through time configured for the system. The
ride-through time, designed to avoid disruption if the power outage is short enough in duration for
a UPS to provide the needed power, is specified through the POWERFAIL_DELAY_TIME attribute
of the SCF command ALTER SUBSYS (for more information, see “Considerations for Ride-Through
Time Configuration” (page 157)).
156 Operations and Management Using OSM Applications